When a plurality of semiconductor elements (chips) are to be stacked, flip-chip bonding is often used. As a device in which an adverse influence of noise between semiconductor chips is reduced, the following semiconductor is proposed. When using flip-chip bonding, a wiring layer included in a flat solid layer formed of a conductive material is arranged between each of the semiconductor chips. By connecting the wiring layer to a ground terminal or a power supply terminal of the semiconductor chip, high-speed transmission can be achieved without causing adverse influence of crosstalk noise between the semiconductor chips.